Honest progression, and the pressure against it
Moving a student up to fill a class harms them.
Progression between levels should reflect readiness and is influenced by class sizes, timetabling and commercial considerations. A student moved up before they are ready spends a term partially comprehending, and their apparent slow progress at the higher level is read as a limitation in them.
The pressure is real and usually not cynical: an under-enrolled higher class, a student who is disappointed not to move, an agent asking questions. Each individual decision is defensible and the pattern harms the students moved.
The protection is criteria applied by teachers, recorded, and reviewed by somebody without a commercial interest in the outcome. Where a student is moved against criteria, that should be a documented exception with a reason rather than an unrecorded accommodation.
Repeating a level is experienced badly and is frequently the right outcome. Framing it as consolidation with specific targets, rather than as failure, changes how it is received, and a teacher explaining it in advance is far better than an administrator confirming it afterwards.
The other feedback that matters is on speaking, which is the skill students most want to improve and the one they receive least specific comment on. Recording a short sample at intervals and letting the student hear the difference is more convincing than any assessment, and it addresses the common belief that no progress is being made.